Process of manufacturing silicon nitrid.



A. SINDING-LARSEN. PROCESS OF MANUFACTURING SILICON NITRID.

APPLICATION FILED MAR.17, 1909.

Patented July 20, 1909.

Witnesses. Wk. $21651.

or, 2.1). connection When barren ermine PATENT orator];

ALF SHTDING-LARSEN, orcunlsrliinm, NORWAY.

PlEtilUEbS UF MANUFAAGTURING SILICON NITRIZD.

, are. sincere.

To all whom it may concern: v

, file it ltnown that l, ALF SINDING-LARSEN, a subject of the King of Norway, residing atllhristiania, Norway, have invented cert n new and useful Improvements in the lFrocess or Manufacturing Silicon Nitrid; and i do hereby declarethe following to be a toll, clear, and exact vdescription of the invention, such-as will enable others skilled in. the art to" which it appertains to make use the same, reference being had to the acc mpanying drawings, and to lettersof hoe marked. thereon, which form a part s specification. 7 Lily invention consists in an improved promise of manufacturing silicon nitrid by causing; silicon. in

tree state to combine with nitrogen,

@ilicon nitrid, which has not heretofore been. produced iii an industrial manner, was

however several years ago pointed out by hiehner (in German patent No. 88999) as a nitrogen compound with a very high per-.

'cent'age of nitrogen, for the manufacture of con car-bid nitrid (carbazotsilicon) such as aiready pointed out by L. Spiegel, More over the nitrogen compounds, which might be formed by this process, cannot without great ditficulties be as aratedfrom the resuiting slag. llhese Clll GilltlGS are overcome by the present process, according to which vap rs or a fine dust of silicon of a high nitr gen,

temperature is acted upon by hot and the silicon nitrid resulting thereby taken up in filtering or deposition chambers, where it is coilected in. the .;torm of a fine dust or powder.

The recess may suitabiy be carried out in ation, s "h the production. of silicon 1 processes, by which silicon is obtained as a residual by-product, curried out in connection with the. man ccture oi? siiicon the process may be Specification 01' Letters "Patent. application filed; Hatch 11, 190W. 8eria1 No. 484,047.

process. 7 a i In this drawing A. represents l ectrode- Patented. July conducted as follows: A charge comprising silica or a silicate together with the amount of carbon necessary for reducing the silica,

is heated in a closed electric furnace inside or outside of which is arranged a chamber for taking up the vapors and gases generated during the reduction process. The furnace is connected through a discharge pipe with suitable filtering or deposition chambers, in which t-he'nitrid is taken up. Nitrogen is introduced into the vapor chamber of the furnace through pipes, which inclos'e or are inclosed in the discharge pipe for the purpose of utilizing the heat carried away by the escaping gases to heat the nitrogen. The nitrogensupplying pipes are preferably arranged in such a manner as to impart a whirling motion to the gases and vapors in the furnace. (The nitrogen may also be introduced through'the electrodes). 'lhereaction between the silica and the carbonin the charge will result in the formation of silicon vapors and carbonic oxid gas, which in the vapor chamber is mixed with the hot nitrogen gas. This latter is preferably introduced in great excess ofthe carbonic oxid. At the high temperature prevailing in the vapor-chamber the silicon vapors and'the silicon dust resulting from the 'vapors being in part condensed, will now combine with the nitrogen forming silicon nitrid as a finev dust, which together with carbonic oxid from the reduction process and surplus nitrogen as well as other gases, which might have been introduced together with the nitrogen are drawn through the above mentioned filtering or deposition chambers,

where the silicon nitrid is taken up. If

necessary the product obtained hereby is afterward purified for instance by washing, magnetic separation or the like.

The nitrogen neccssary'for carrying out the process may be obtained in a sufficiently pure condition from atmospheric air for instance by burning in this latter the carbonic oxid obtained in the reduction process men tinned above. By taking, the carbonic dioxid formed thereby up into a suitable absorbent for instance Water, limeor the like, a gas consisting mainly of nitrogen, is. ob-

tained.

nit

In the accompanying drawing is fillus" trated an arrangement of apparatus, which might be employed in carrying abuhthe furnace with an upper electrode 13 and a bottom electrode C, the crucible shaped furnace chamber being covered by a lid D. The furnace is connected throughthe flue E with deposition chambers F, from which the gases are drawn through a combustion apparatus G into which air is introduced through the the opening 0 in the furnace cover D.

The process may also be carried out in connection with the manufacture of silicids.

These latter, especially ferrosilicon, are usually produced in an electric furnace by reducing silica or silicates, to which is added the metal or an oxid of the metal in question and other substances. According to the manner in which the furnace is worked during these processes, whether a high or low temperature, or a more or less covered arc is employed, and according to the concentration of the silicid, a greater or smaller part (up to about per cent.) of the silicon liberated during the process will be volatilized, and this part of the silicon has hitherto represented a loss, which may be avoided by utilizing the silicon vapors in the manufacture of silicon nitrid in accordance with the above described process. By utilizing the escaping silicon vapors in this way the s licid production would be made much more profitable than it is at present possible. f a

The constructive arrangement of the vapor and gas. reaction chamber, the nitrogen supply and the apparatus for collecting the silicon nitrid may as a matter of course be modified according to the 'circumstancesin. each specific case. i

The silicon and nitrogen employed in the process may be produced in any proper way, but in every case to these bodies should be causing a reaction to take place.

Claims.

process which consists 1n producing vapors 2. In the production of silicon nitrid the ing the same to be acted uponby an atmos phere containing heated nitrogen gas? process which consists in producing 'an'atsame to be acted upon by'an atmosphere containing heated nitrogen gas. v 4. In the production of sillcon nitrid the with an electric furnace, feeding material to the furnace for the production of silicon by a reduction process at a temperature causin a vaporizing of the whole or part of the 'sil1- conformed. t

5. In the production of silicon nitrid the process, which consists in establishing an atmosphere chiefly containing nitrogen gas in with an electric furnace, feeding material to the furnace for the production of silicids l and silicon at a temperature causing a vapl orizing of .the silicon.

of silicon by heating a 'silicid and causing the same to be acted upon by gaseous nitro gen in heated condition.

my invention, I have sighed my name in presence of two subscribing W tnesses.

ALFQSINDINGLARSEN;

- Witnesses:

HENRY Bonnnwron, AUG. OLSEN.

imparted the high temperature necessary for of silicon and causing the same to be acted upon by gaseous nitrogen in heated COIldltlOIl.

mosphere containing vapors of siliconand cooling the same so as to obtain finely (11- VlClGd particles of s1l1con and causing the.

process which consistsin establishing an atinosphere chiefly contalnlng nitrogen gas 1111 a chamber forming part, of or connected" a chamber forming part of or connected.

6. In the production of silicon nitridthe. process, which consists in producing vapors In testimony that I claim the foregoing as f 1. In the production of silicon nitri d the process, which consists "in producing an 313 i mosphere, co'ntalnmg vapors of silicon and finely divided particles of 81110011 and cans-' 3. In the production of silicon nitrid the I 

